A sensitive assay based on specific aptamer binding for the detection of Salmonella enterica serovar Typhimurium in milk samples by microchip capillary electrophoresis

作者：Zhang, Yan; Luo, Feifei; Zhang, Yating; Zhu, Luqi; Li, Yi; Zhao, Shuangli; He, Pingang; Wang, Qingjiang^*

来源：Journal of Chromatography A, 2018, 1534: 188-194.

DOI：10.1016/j.chroma.2017.12.054

• Salmonella enterica serovar
• Typhimurium
• Microchip capillary electrophoresis
• Fluorescent dye
• Aptamer
• Bacteria
• Milk sample

The detection of Salmonella enterica serovar Typhimurium (S. Typhimurium) is very important for the prevention of food poisoning and other infectious diseases. Here we reported a simple and sensitive strategy to test S. Typhimurium by microchip capillary electrophoresis couple with laser-induced fluorescence (MCE-LIF) based on the specific reaction between the bacterium and corresponding aptamers. Based on the differences in charge to mass ratio between bacteria-aptamer complexes and free aptamers, a separation of the complexes and free aptamers could be obtained by MCE. The optimal parameters of the specific reaction including fluorescent dye concentration, Mg2+ concentration, incubation time, and pH of incubation solution were carefully investigated. Meanwhile, a non-specific DNA was exploited as a contrast for the detection of S. Typhimurium. Under the optimal conditions, a rapid separation of the bacteria-aptamer complex and free aptamers was achieved within 135 s with a limit of detection (S/N =3) of 3.37 x 10(2) CFU mL(-1). This method was applied for the detection of S. Typhimurium in fresh milk samples and a recovery rate of 95.8% was obtained. The experimental results indicated that the specific aptamers are of enough biostability and the established method could be used to analyze S. Typhimurium in foods.

• 出版日期2018-1
• 单位华东师范大学